Thunder maul - Dragon Low FPS miss feeding

[ScooterVauto]

Hi Iggy.
when testing the m4 is full assembled, all pins, mag release, buffer tube etc

I tried a different Mechbox incombonation with both upper hopups No change (unless you apply a little backward pressure then it works).
I think my problem Is the Upper receiver, its like it doesnt hold the hopup back far enough
for the nozzel to seal (its less then 1mm)

soo it the upper receiver
I used the upper from my M4 (the one that ususally runs the SystemAhopup assembly with the 455 Promy)
Put it on the JG lower -- 375 FPS all day long
So the upper us preventing the hopup from properly pressing against the bbs chase and Mechbox.

[R.I.T.Z]

see that little pen spring? that pushes the hop up unit back against the mech box.
do you have the piece?

[ScooterVauto]

yup & so is the brass ring (saves asking )
FYI its a 2 piece hopup
(for clarity sake )

I think I'll take a hopup nub, set it inside the coils of the spring (just ahead of the area the pin will be in) to see if i can stiffen the spring a bit thus pushing it back that tiny bit i need .

[Styrak]

Originally Posted by ScooterVauto

yup & so is the brass ring (saves asking )
FYI its a 2 piece hopup
(for clarity sake )

I think I'll take a hopup nub, set it inside the coils of the spring (just ahead of the area the pin will be in) to see if i can stiffen the spring a bit thus pushing it back that tiny bit i need .

Yeah or put something inside the upper so the hopup can't go as far in. Or put a longer/stronger spring on the hopup?

[ScooterVauto]

well i put a nub inside the coils of the spring and the FPS jumped upto 324.
Defninatley the right track.
Now where in the heck am i going to get a strong spring, Longer isnt needed and this
one i am sure is from a pen hahaha
I have 1 idea left, I have some foam rubber that is adhesive on 1 side, I'll cut a luutle cube and stick it to the point where the spring meets the body.

thanks for all the help folks, I'll keep you updated
SV

[Styrak]

Sounds like an idea.

This is so exciting! Riveting even! Can't wait for the next update! Lol.

[ScooterVauto]

Hey boys sorry i have not had a chance to work on the maul since our last time together

NAR stuff i am sure you can understand.
I had to dismantle it, I had assembeld it totally and when i went to put the
battery in, To my surprize, the new outter i put on it JUST thick enough
to prevent the battery for going in hahahaha
SOOO back to the Machinest at work to Mill a few mils of the top side of the outter.
I should have a final update friday night
Be well and again thank you for the Assistance so far,
SV

[Styrak]

You got a new outer barrel? Where did this new info/idea come from?

[ScooterVauto]

well well well, the factory inner was WICKED worn out, The Box had a plated cylinder
that was sooo used there was NO inner plating left.



sorry bout the date, my dvd still blinks 12:00 hhahaha

the barrel was scored and savage looking so i had a 7 inch inner and outter from a Dboys Ris i had SOOO in they went

I had the machinest lathe off the front sight stop and the paint off the front end to match the silver and black that IS the thunder mail.

Personally, If i ever find one for my self..... well lest just say i have MB already set up with a 1.7J spring and The gears to drive them..
And a 455mm PDI Inner but thats just me
(id basically pull the Ris off my VLTOR and wrap the maul body around it hahaha I'll need a Mosfet and lipo to run it tho hahaha Soory pipe dream

Here is the Spring hopup nub mod

[CerberusNet]

Originally Posted by ScooterVauto

so are you ready for this,
Took the stock hopup, with the dboys barrel and the green hopup rubber,
HELD it to the Front on the assembled bottom half and
it shoots 350???
put it in the upper and put them together 216??
Itslike the upper hopup assembly is not sealing against the lower bb chase thus a seal leak..

A few theories..Obviously you would have to trial and error to see if any are accurate but when I was reading I had a few come to me. Hopefully at least one of them puts you on the path to a proper solution.
Please keep in mind what Styrak mentioned.."Swap one part at a time or you'll never figure it out "

1-Experience has shown me that G&Gs green hopup buckings are problematic and I've had to change 1in3. More commonly I found they just had an assembly issue and a new one would work, with a small amount of lube.

Originally Posted by ScooterVauto

well i put a nub inside the coils of the spring and the FPS jumped upto 324.
Defninatley the right track.
Now where in the heck am i going to get a strong spring, Longer isnt needed and this
one i am sure is from a pen hahaha
I have 1 idea left, I have some foam rubber that is adhesive on 1 side, I'll cut a luutle cube and stick it to the point where the spring meets the body.

2-This reminded me of a method I use for increasing output of pellet guns, but if the very creative "Spring hopup nub mod" has solved that problem there's no need for it.
If you have 2 springs of similar size, you can twist or coil them together, this will effectively increase the strength of the spring and will not change the size if done correctly.

3-The barrel needs to be replaced, as it is very worn. I had a theory it might be early on, then noticed you had already found it.

I don't think there was a problem with the seals of the cylinder and shaft, or the piston head, because it would have been a constant problem, it most likely seems like a problem outside of the mechbox.

By the pics, your machinest is pretty accurate. Is he available to the public? I could use a good metalworker hand.

[ScooterVauto]

alrighty folks here we Go.
The G&G was replaced with a guarder black and stock nub (not the one in the spring)
The speed did not change.
So here is the 7inch (i think) outter with the paint and sight stop machined off

i had to sand some off the colloar bottom to fit the forward grip of the maul body.


here is the channel cut to allow the battery in
(cleaned up a little with the dremel and an 80 grit paddle wheel)



So as i had mentioned i put a little piece of self adhesive foam rubber


in the receiver where the Hopup meets the body.


i assembled the rifle and it looks alot like an armalite huh hahahah


here is the barrel upclose


the speed jumped to 345 for a few shots then settled at 320,

as you can see the hopup does make contact with the rubber .


So i added a peice to the Hop up its self


the speed jumped to 354 then settled into a 339 to 345 and stayed there for 30+ bbs.
For the age of the kit with the Few parts added its consistant enough to play and range it in.

Now i had to dremel out a few places on both sides of the body.



the battery area needed a little material removal to allow the battery to slide into the body,
but the top back of the outter barrel collor will need some dremel work as the battery doesnt go all the way in

I had to machine out the area infornt of the delta ring for the wider outter barrels collar.


I had to dremel out the area that wraps around the end of the outter barrel



and here it is with a bird cage from my M733


Admin please label this thread as solved (well somewhat )
and 56 K death

Thank you again everyone.
SV

[R.I.T.Z]

needs a shorter barrel, a silencer, a drum mag, and some pimp paintjob

[Spawn28]

i cant get passed the Pen-is on the front hand grip but good to hear you mostly solved the issue.

[Amos]

Adding that little block of foam rubber to the hop-up wouldn't effect the amount of hop. What it's doing is pushing the upper part of the unit against the air nozzle to create a better seal.

Your problem here is your hop-up chamber... I'd suggest modifying the lower to accept a 1 piece hop chamber... I have a feeling that would solve all of your problems.

[ScooterVauto]

Hi Amos.
your knowledge as always is apprciated.
THe owner of the rifle would prefer not to Cut up the lower receiver.
But for clarity, it wasnt hopup we were going for, but a better seal as there was an
issue with the hopup rubber/nozzel seal due to A percieved weak spring,
without access to a new spring, We returned to Piano wire and prayer for a fix